安徽淮河流域黄鳝繁殖生物学特性的初步研究

对2004年3～5月选购的210尾野生黄鳝进行了体长、体重、年龄与性别及其雌鳝怀卵量进行测定分析.结果表明,Ⅰ龄组亲鳝全部为雌性,Ⅱ～Ⅲ龄组为雌雄间体阶段,Ⅳ龄组多为雄性个体,Ⅴ龄基本上都已逆转为雄性;雌雄个体体长分布的交界点为47.0 cm,交界点以下范围雌性占优势,以上范围雄性占优势;雌雄个体体重分布的交界点为95 g,交界点以下范围雌性占优势,以上范围雄性占优势.性腺发育随水温变化显著,雌性个体绝对怀卵量与体长呈幂函数关系:Y=1 192ln(x)-3 579.由此认为,利用黄鳝体长与体重的重合交界点性状指标作为参考,是较准确地选择雌雄亲鳝进行配组培育或直接催产比较适用的方法.

Preliminary Research on the Biological Characteristic of Mud Eel's Reproduction of Huaihe Valley in Anhui Province

Two Hundred and ten wild mud eels in March-May of 2004 were measured on age,length,weight,sex,gonad development and amount of ovum cherished.The result shows that the parent eels in the first age group are all female,in the second and the third age groups are in the stage of intersexes development.The forth age group includes more male individuals than female.In the fifth age group,the mud eels are almost all reversed to male.The point of intersection in length of male and female individuals is 47.0 cm.On the level of intersection,the females are preponderating,while above the level,males are preponderating.The point of intersection in weight is 95 g.Under the level of intersection,the females are preponderating,while above the level,males are preponderating.The gonad development changed briefly with the water temperature.The absolute amount of ovum cherished of female individuals and length are the exponential functional relation:Y=(1 192)ln(x)-3 579.In that case,using the coincidence of the point of intersection of length and weight to choose parent eels to mix the group or hasten lay directly is a point idea.